Zhu, Shijun published the artcileSynthesis and Configuration of Neomaclafungin A, Product Details of C21H37BO, the publication is Chemistry – An Asian Journal (2017), 12(17), 2211-2215, database is CAplus and MEDLINE.
The relative and absolute configuration of neomaclafungins were impossible to establish by spectroscopic analyses alone because of the lack of exploitable 1H-1H couplings and NOEs between the upper and the lower subunits. This very difficult task now is finally completed by an enantioselective total synthesis of neomaclafungin A (revised) and its diastereomer (reported). The results also provided a key reference for the complete structures for other neomaclafungins and the long-known closely related natural product maclafungin.
Chemistry – An Asian Journal published new progress about 99438-28-5. 99438-28-5 belongs to ethers-buliding-blocks, auxiliary class Chiral,Aliphatic cyclic hydrocarbon, name is (+)-B-Methoxydiisopinocampheylborane, and the molecular formula is C18H24N6O6S4, Product Details of C21H37BO.
Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem